This article is complete bunkum. 9.0L (Longhorn) was renamed to 9.0Ex (Extended, to support "features such as cross-process shared surfaces, managed graphics memory, prioritization of resources, text antialiasing, advanced gamma functions, and device removal.") long ago. 9.0Ex is the version of directx 9 that will be built into Vista to enable backward compatability for dx9 and earlier games/apps to run ON VISTA. 9.0Ex will not be available on winXP as it is not needed, 9.0c is the last version of dx for xp.